Abstract
Renal vein thrombosis is a rare lesion seen principally in the neonatal period. We recently encountered an 11-day-old boy with bilateral intra-renal vein thrombosis, who was treated conservatively with anti-coagulant therapy. Such patients, however, require long, carefull follow-up because of possible renal hyper-tension or nephrosis secondary to the successfully treated renal vein thrombosis. In this case report, diagnosis and treatment of renal vein thrombosis are also discussed.